Can say that I've tried senna again recently and the results were fun! Certainly more so than my earlier dabblings too.
Side note: I like senna for keeping my belly feeling “active” and making the peristalsis particularly pronounced. I suffer from chronic constipation so feeling activity in my belly is reassuring and kinkily satisfying. Senna is certainly cramp-inducing which I love, but unlike other stimulant laxatives, it also brings with it a lot of “pressure”, like my intestines are working away at full-strength even when there's nothing in 'em for hours on end. I love the sensation and urgency throughout, and it typically lasts around 6-8 hours after kicking in (usually 4 hours after taking it).
I mainly use extra-strength (25mg) generic senna tablets, but have been trying tea as well. The tea I used a ways back is TeaWell Senna tea which stubbornly obfuscates the amount of senna leaves in it as part of its “proprietary” blend, but it seems to have a similar effect to around 10-20mg of senna per teabag. Tripling up on such provides a decent effect, though nothing truly urgent. A teabag or two is nice for mild constipation though.
Last night, I took 2 senna tablets (50mg) before bed at midnight. Then I woke up fours hours later in the night with a noticeable pressure, mild cramping and rumbling in my belly. I decided to take the last of my senna bottle's tablets (4 tablets, so 100mg; 150mg total) as I was feeling particularly masochistic and went to bed again.
3 hours later at 7:00am was a powerful urge to go. No diarrhea or such either. Though it barely did anything to calm the storm in my belly. I felt bloated and there was clearly more left in me to push out. Another two hours of feeling the moderate cramping and gurgling in my gut and then came a lurch of pressure. It was what I would certainly call “urgent!” Out came probably most of what I ate the day before, and only then did the pressure subside.
I decided to squeeze in an enema around that time just for good measure. Prepped a 4-quart plain hot water (106°F) enema and got it flowing. The sensation was interesting as I definitely felt the laxative was still working its magic on my bowels. I could feel the pulsing peristalsis trying to push the water out at my sigmoid and transverse colon around the 2-quart mark, but I managed to get another quart in before the cramps became too mind and I had to stop pre-emptively.
The emptying was fast and it was marvelous to feel my guts hurriedly squeeze out the water. It barely took any pushing to let it all out (with no return trips unlike typical plain water enemas). I wish I could've taken the full bag, but such is the nature of stimulant laxatives really activating the colon.
It's around 1pm now and I still feel the residual effects of the senna working in me. I'm tempted to try another 4-quart enema just to see if I can get it all in and feel that lovely emptying sensation once more!